Replacing the measles ten-dose vaccine presentation with the single-dose presentation in Thailand.

Introduced to minimize open vial wastage, single-dose vaccine vials require more storage space and therefore may affect vaccine supply chains (i.e., the series of steps and processes involved in distributing vaccines from manufacturers to patients). We developed a computational model of Thailand's Trang province vaccine supply chain to analyze the effects of switching from a ten-dose measles vaccine presentation to each of the following: a single-dose measles-mumps-rubella vaccine (which Thailand is currently considering) or a single-dose measles vaccine. While the Trang province vaccine supply chain would generally have enough storage and transport capacity to accommodate the switches, the added volume could push some locations' storage and transport space utilization close to their limits. Single-dose vaccines would allow for more precise ordering and decrease open vial waste, but decrease reserves for unanticipated demand. Moreover, the added disposal and administration costs could far outweigh the costs saved from preventing open vial wastage.

Prevention of varicella: recommendations of the Advisory Committee on Immunization Practices (ACIP).

Two live, attenuated varicella zoster virus-containing vaccines are available in the United States for prevention of varicella: 1) a single-antigen varicella vaccine (VARIVAX, Merck & Co., Inc., Whitehouse Station, New Jersey), which was licensed in the United States in 1995 for use among healthy children aged > or = 12 months, adolescents, and adults; and 2) a combination measles, mumps, rubella, and varicella vaccine (ProQuad, Merck & Co., Inc., Whitehouse Station, New Jersey), which was licensed in the United States in 2005 for use among healthy children aged 12 months-12 years. Initial Advisory Committee on Immunization Practices (ACIP) recommendations for prevention of varicella issued in 1995 (CDC. Prevention of varicella: recommendations of the Advisory Committee on Immunization Practices [ACIP]. MMWR 1996;45 [No. RR-11]) included routine vaccination of children aged 12-18 months, catch-up vaccination of susceptible children aged 19 months-12 years, and vaccination of susceptible persons who have close contact with persons at high risk for serious complications (e.g., health-care personnel and family contacts of immunocompromised persons). One dose of vaccine was recommended for children aged 12 months-12 years and 2 doses, 4-8 weeks apart, for persons aged > or = 13 years. In 1999, ACIP updated the recommendations (CDC. Prevention of varicella: updated recommendations of the Advisory Committee on Immunization Practices [ACIP]. MMWR 1999;48 [No. RR-6]) to include establishing child care and school entry requirements, use of the vaccine following exposure and for outbreak control, use of the vaccine for certain children infected with human immunodeficiency virus, and vaccination of adolescents and adults at high risk for exposure or transmission. In June 2005 and June 2006, ACIP adopted new recommendations regarding the use of live, attenuated varicella vaccines for prevention of varicella. This report revises, updates, and replaces the 1996 and 1999 ACIP statements for prevention of varicella. The new recommendations include 1) implementation of a routine 2-dose varicella vaccination program for children, with the first dose administered at age 12-15 months and the second dose at age 4-6 years; 2) a second dose catch-up varicella vaccination for children, adolescents, and adults who previously had received 1 dose; 3) routine vaccination of all healthy persons aged > or = 13 years without evidence of immunity; 4) prenatal assessment and postpartum vaccination; 5) expanding the use of the varicella vaccine for HIV-infected children with age-specific CD4+ T lymphocyte percentages of 15%-24% and adolescents and adults with CD4+ T lymphocyte counts > or = 200 cells/microL; and 6) establishing middle school, high school, and college entry vaccination requirements. ACIP also approved criteria for evidence of immunity to varicella.

Residual susceptibility to measles among young adults in Victoria, Australia following a national targeted measles-mumps-rubella vaccination campaign.

BACKGROUND: Past measles immunisation policies in Australia have resulted in a cohort of young adults who have been inadequately vaccinated, but who also have low levels of naturally acquired immunity because immunisation programs have decreased the circulation of wild virus. A measles-mumps-rubella (MMR) immunisation campaign aimed at addressing this susceptibility to measles among young adults was conducted in Australia in 2001-2. By estimating age-specific immunity, we aimed to evaluate the success of this campaign in the state of Victoria. METHODS: We conducted serosurveys after the young adult MMR program at state and national levels to estimate immunity among young adults born between 1968-82. We compared results of the Victorian (state) surveys with the Victorian component of the national surveys and compared both surveys with surveys conducted before the campaign. We also reviewed all laboratory confirmed measles cases in Victoria between 2000-4. RESULTS: The Victorian state serosurveys indicated no significant change in immunity of the cohort following the young adult MMR campaign (83.9% immune pre and 85.5% immune post campaign) while the Victorian component of the national serosurvey indicated a significant decline in immunity (91.0% to 84.2%; p = 0.006). Both surveys indicated about 15% susceptibility to measles among young Victorian adults after the campaign. Measles outbreaks in Victoria between 2000-4 confirmed the susceptibility of young adults. Outbreaks involved a median of 2.5 cases with a median age of 24.5 years. CONCLUSION: In Victoria, the young adult MMR program appears to have had no effect on residual susceptibility to measles among the 1968-82 birth cohort. Young adults in Victoria, as in other countries where past immunisation policies have left a residual susceptible cohort, represent a potential problem for the maintenance of measles elimination.

Impact of vaccine economic programs on physician referral of children to public vaccine clinics: a pre-post comparison.

BACKGROUND: The Vaccines for Children (VFC) Program is a major vaccine entitlement program with limited long-term evaluation. The objectives of this study are to evaluate the effect of VFC on physician reported referral of children to public health clinics and on doses administered in the public sector. METHODS: Minnesota and Pennsylvania primary care physicians (n = 164), completed surveys before (e.g., 1993) and after (2003) VFC, rating their likelihood on a scale of 0 (very unlikely) to 10 (very likely) of referring a child to the health department for immunization. RESULTS: The percentage of respondents likely to refer was 60% for an uninsured child, 14% for a child with Medicaid, and 3% for a child with insurance that pays for immunization. Half (55%) of the physicians who did not participate in VFC were likely to refer a Medicaid-insured child, as compared with 6% of those who participated (P < 0.001). Physician likelihood to refer an uninsured child for vaccination, measured on a scale of 0 to 10 where 10 is very likely, decreased by a mean difference of 1.9 (P < 0.001) from pre- to post-VFC. The likelihood to refer a Medicaid-insured child decreased by a mean of 1.2 (P = 0.001). CONCLUSION: Reported out-referral to public clinics decreased over time. In light of increasing immunizations rates, this suggests that more vaccines were being administered in private provider offices.